Referring to FIG. 1, the structural schematic view about a prior art encoder is illustrated. The encoder 100 has a cover 1, a disk 2, a reading head 3 and a bottom plate 4 which are combined as an encoder module 100. In assembly, the reading head 3 serves to read signals from the disk 2. Then a screw 6 serves to combine the reading head 3 with the bottom plate 4. Then the cover 1 covers the structure. Finally, a disk 2 is connected thereto so as to form as an encoder module. Finally, the cover 1 covers the structure. In this prior art, the screw is deadly locked so that it is difficult to update the reading head 3 and disk 2. Furthermore, the disk 2 is easy to be damaged.
Thus, the prior art encoder module is inconvenient and is necessary to be updated.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.